R-39 / SS-N-20 STURGEON
The R-39 solid-propellant intercontinental missile is a three-stage missile with multiple re-entry vehicles. The post-boost vehicle has a guidance system, a liquid fuel propulsion system and 10 blunt shaped MIRVed warheads that are smaller than warheads carried on previous missiles. The warheads are located on the rear unit of a post-boost vehicle, around the nozzle of the third stage engine. The R-39 is intended for the defeat of strategic targets at the intercontinental distances. It is accepted for the armament the Navy in 1983. Rocket is placed on the submarines of project 941 with the fire unit of 20 rockets.
New technical solutions, realized in the rocket:
rocket engines on the high-energy solid fuel with the use of new construction materials;
- control system, which uses principle of the generalized celestial correction;
- the high-speed small warheads ["combat blocks"] of the increased specific power;
- the amortization rocket-starting system, which ensures storage, transport and the launch of rocket;
- the aggregates of ground-based technological equipment at the railroad motion (with the cockless transfer of rockets) and the complex of the means of their loadings, which ensure safety of the operation of rockets.
The R-39 rocket includes a three-stage solid fuel booster, amortization rocket-starting system ([ARSS]) and divided head part ([RGCH]). They enter into the composition of head part: combat equipment of 10 combat blocks, equipment of control system and the liquid propellant rocket engine, which ensures the individual guidance of combat blocks to the target.
The missile is suspended in the launch tube from a special control mounted in the nose cone, with a reference ring at the top of the tube functioning as the launch support. In the launch tubes [literally "mine"] of submarine the rocket is in a suspended state, relying on the launching platform (carrier ring), located in the upper part of the tube. The ARSS ensures the amortization of rocket, hermetic sealing the cavity of mine and safety of rocket for the submarine, it allows the submerged submarine rocket carrier from the tube to the significant depth opened by cover. All load-bearing elements of rocket, necessary with its operation on the ground environment and aboard the ship, with exception of middle supporting skirt, are placed on the ARSS and housing of rear compartment, jettisoned in the initial phase of flight after the output of rocket from the water.
The dry launch from the tube is accomplished with a gas generator located on the bottom of the tube in a cavity of the first stage engine nozzle. Missile takeoff is achieved from "dry" tube with the aid of the solid-propellant gas generator, placed on the bottom of mine in the engine nozzle of first stage. During lift-off special solid-propellant charges create a gas bubble around the missile considerably reducing hydrodynamic resistance. At the moment of launch a special solid-propellant grain, located on the ARSS, create the gas current protection in the form of cavity, which decreases the hydrodynamic loads on the rocket. Command to the starting of first-stage engine will be given at the moment of the output of rocket from the tube. Ignition of the first stage engine occurs after leaving the tube. With start of the first-stage engine after exiting from the water the rocket for the purpose of providing safety of submarine takes away to the side. Starting system in flight is removed by special engines from the rocket and also it takes away to the side.
Flight control during the active leg of the first stage is attained by injecting gases from the combustion chamber of the sustainer into the nozzle through 8 symmetrically located injection valves. The engines of the second and third stage used gimbaled nozzles for guidance. Instrument compartment with the cupola is located in the nose section of rocket. It is joined with the housing of the post-boost control system - PBCS - [literally "step of breeding"] with the aid of a flanged joint. Together they form the divided head part. Instrument compartment consists of two airtight, divided by intermediate bottom sections: it cut off three-stage gyrostabilizer with the astroing-sight device, closed with the expendable in flight cupola, and cut off control-system equipment, located on the amortization frame. The PBCS is butted with the instrument compartment, in it combat blocks are placed. The two-mode liquid engine installation of MIRVing and separable third-stage engine is installed on the housing of the post-boost control system.
Work on the R-39 missile and the D-19 launch system began in 1971 by NII Mashinostroyeniya (chief designer V. P. Makyeyev). Development was officially authorized in September 1973. Flight testing was conducted in several phases. Initially two series of dry launches were carried out, nine from a floating platform and seven from a specially adapted submarine. Due to first and second stage engine problems more than half of the 17 flight tests at the Central Naval Test Training Site at Nenoksa were unsuccessful. After resolution of the engine problems 11 out of 13 launches from the "TK-208" Typhoon submarine were carried out successfully.
After intensive testing on board the "TK-208" submarine, deployment began in 1984. The large Typhoon submarines were outfitted with 20 R-39 missiles each.
Soon after deployment work began on an advanced version with greater accuracy and greater warhead coverage. Deployment of the modernized missile began in 1989.
By 2004 the three remaining project 941 (Akula) subs assigned to the 19th division of the Northern Fleet were still armed with the D-19 missiles. By 2004 almost all these missiles had been utilized by launching. One sub [Severstal] still had 10 missiles, half the full load, but in the near future they will be launched and destroyed. This type of missiles is not in the production any more. On 29 April 2004 the CinC of the Russian Navy, Admiral Vladimir Kuroedov, convened a meeting on the future of the Typhoon submarines at which it was decided that the subs will be scrapped.